A machining tool assembly is provided for machining a blank to form a firearm lower receiver. The assembly includes a pair of side plates positionable on opposed sides of the blank to capture the blank therebetween. A template plate having a template aperture is adapted to be removeably attachable to the side plates. The template aperture is aligned with a top surface of the blank and is adapted for machining a cavity within the blank having a peripheral contour complimentary to a peripheral contour of the template aperture. A centering mechanism is adapted to be removeably attachable to the template plate, with the centering mechanism including an opening aligned with a corresponding void formed on the blank to align the blank with the template plate.

A drill bushing for a drill unit. In one embodiment, the drill bushing includes a base member having an upper surface, a lower surface configured to rest on a workpiece having a pilot hole, and a retaining member that projects from the lower surface of the base member. The retaining member has a cylindrical outer diameter that fits within the pilot hole. The drill bushing further includes a drill hole that passes from the upper surface of the base member through the retaining member to provide a passage for a drill bit. The drill bushing further includes an expandable slit that passes through the base member and the retaining member to the drill hole, and an adjustment member configured to expand the expandable slit to increase the cylindrical outer diameter of the retaining member within the pilot hole.

A drill bushing for a drill unit. In one embodiment, the drill bushing includes a base member having an upper surface, a lower surface configured to rest on a workpiece having a pilot hole, and a retaining member that projects from the lower surface of the base member. The retaining member has a cylindrical outer diameter that fits within the pilot hole. The drill bushing further includes a drill hole that passes from the upper surface of the base member through the retaining member to provide a passage for a drill bit. The drill bushing further includes an expandable slit that passes through the base member and the retaining member to the drill hole, and an adjustment member configured to expand the expandable slit to increase the cylindrical outer diameter of the retaining member within the pilot hole.

A machining tool assembly is provided for machining a blank to form a firearm lower receiver. The assembly includes a pair of side plates positionable on opposed sides of the blank to capture the blank therebetween. A template plate having a template aperture is adapted to be removeably attachable to the side plates. The template aperture is aligned with a top surface of the blank and is adapted for machining a cavity within the blank having a peripheral contour complimentary to a peripheral contour of the template aperture. A centering mechanism is adapted to be removeably attachable to the template plate, with the centering mechanism including an opening aligned with a corresponding void formed on the blank to align the blank with the template plate.

A wing skin, which was secured to a wing structure by a plurality of fasteners extending through the wing skin, is removed from the wing and aligned with a template. Template holes are drilled through the template corresponding to each of the fastener holes of the wing skin. The template is then aligned with a new wing skin, and pilot holes are drilled through the new wing skin corresponding to each of the template holes. The new wing skin is then aligned with the wing structure such that the pilot holes permit access to corresponding fastener holes of the wing structure. A mill bit is then positioned through each pilot hole and aligned with the center of the corresponding consumable bushing in the fastener hole of the wing sub-structure, and the skin pilot holes are milled to form fastener holes in the new wing skin aligned with existing sub-structure.

A wing skin, which was secured to a wing structure by a plurality of fasteners extending through the wing skin, is removed from the wing and aligned with a template. Template holes are drilled through the template corresponding to each of the fastener holes of the wing skin. The template is then aligned with a new wing skin, and pilot holes are drilled through the new wing skin corresponding to each of the template holes. The new wing skin is then aligned with the wing structure such that the pilot holes permit access to corresponding fastener holes of the wing structure. A mill bit is then positioned through each pilot hole and aligned with the center of the corresponding consumable bushing in the fastener hole of the wing sub-structure, and the skin pilot holes are milled to form fastener holes in the new wing skin aligned with existing sub-structure.

A drill guide includes a shaft, a drill guide assembly securable to the shaft, and a first drill guide insert. The drill guide assembly includes a first drill guide body defining a receiving passage, a locking member, and terminating in a first grasping projection that flexes between open and closed positions. The first drill guide insert installs in the receiving passage and includes a bore, a grasping projection displacement surface, a locking groove, and a key member. The grasping projection displacement surface moves the first grasping projection from its closed position to its open position during installation of the first drill guide insert. Upon installation, the locking groove receives the first grasping projection to lock the first drill guide insert in the first drill guide body, and the key member engages the locking member to prevent rotation of the first drill guide insert within the first drill guide body.

A wing skin, which was secured to a wing structure by a plurality of fasteners extending through the wing skin, is removed from the wing and aligned with a template. Template holes are drilled through the template corresponding to each of the fastener holes of the wing skin. The template is then aligned with a new wing skin, and pilot holes are drilled through the new wing skin corresponding to each of the template holes. The new wing skin is then aligned with the wing structure such that the pilot holes permit access to corresponding fastener holes of the wing structure. A mill bit is then positioned through each pilot hole and aligned with the center of the corresponding consumable bushing in the fastener hole of the wing sub-structure, and the skin pilot holes are milled to form fastener holes in the new wing skin aligned with existing sub-structure.

A wing skin, which was secured to a wing structure by a plurality of fasteners extending through the wing skin, is removed from the wing and aligned with a template. Template holes are drilled through the template corresponding to each of the fastener holes of the wing skin. The template is then aligned with a new wing skin, and pilot holes are drilled through the new wing skin corresponding to each of the template holes. The new wing skin is then aligned with the wing structure such that the pilot holes permit access to corresponding fastener holes of the wing structure. A mill bit is then positioned through each pilot hole and aligned with the center of the corresponding consumable bushing in the fastener hole of the wing sub-structure, and the skin pilot holes are milled to form fastener holes in the new wing skin aligned with existing sub-structure.

A drill block and a method for drilling a hole through a workpiece using the drill block. The drill block may include a mounting leg for mounting the drill block, a drilling support leg having a round hole therethrough operable to receive a drill bit during a drilling operation, and a height variability leg interposed between the mounting leg and the drilling support leg, wherein the height variability leg is adjustable to select a vertical height of the drilling support leg relative to the mounting leg.